There are many industrial machines, apparatuses, and applications that emit high levels of noise. In many cases, the unwanted noise is generated by movements of internal parts and external casings. Such high levels of noise are generally undesirable. For instance, subjecting industrial personnel to increased noise may not only be bothersome, but may also be harmful to their health. In addition, excessive noise may potentially cause damage to other apparatuses and/or the machines themselves, potentially reducing their life and increasing maintenance costs. For these and other reasons, legislation is being contemplated, and, in some instances, is currently in place, to require the reduction of noise in industrial applications.
Current methods of reducing noise include passive methods for damping sound. Sound dampening may involve placing padding around noisy machines and/or using thick walls of sound-absorbing materials in industrial environments. While more effective than not using any noise reduction at all, these passive methods suffer from several problems. For example, adding thick padding or walls adds to the weight, bulk, and volume of a machine, increasing the amount of space required to run the industrial application, and hence inflating its cost.
In some instances, certain types of noise may be difficult, if not impossible, to reduce or dampen completely using passive methods. Examples of such noises that are challenges for passive methods include loud pulses (e.g., pressure pulses from pumps and related applications), low frequency noise profiles (e.g., intense noise profiles), and resonating noises.
Accordingly, other structural configurations and methods of reducing noise are desired.